1. Field of the Invention
The invention relates to a film having an imprinted antenna, for use with an RFID chip. The antenna consists of a conductor track with connector ends.
2. The Prior Art
RFID (radio frequency identification) chips are active or passive circuits that can be read out with a reader device, in contact-free manner, and are suitable for goods identification. A label film having an imprinted half-wave dipole antenna is known from International Application Publication No. WO 03/068874 A1. In this connection, antennas having full-surface conductor tracks are imprinted on the label film. The antennas are formed from a conductor track having two conductor track pieces.
United States Patent Application Publication No. 2003/080903 A1 relates to a dipole antenna in which a plurality of symmetrically shaped conductive structures that are spaced apart from one another are applied to a dielectric carrier plate. Between the structures that are spaced apart, there are additional coupling structures that are applied separately. This antenna is used for headsets of mobile telephones and allows a reduction of the construction size as compared to a usual half-wave dipole antenna, in which the length of the conductor track pieces correlates directly with the wavelength.
A tunable antenna on a flexible substrate for the high-frequency range is known from US Patent Application Publication No. 2002/0003496 A1. The antenna has full-surface conductor tracks and additional, separable conductor structures for tuning the antenna. Compared with an antenna designed for a fixed frequency, having conductor tracks that extend proceeding from connector ends, the production of the additional structures requires many times the amount of conductive antenna material.